Therefore the contrast between hierarchic classification and gradualistic evolution, which would leave behind an overlapping blurred and fundamentally indistinct pattern, could not be more complete. Nature is fundamentally non-sequential, in other words, a discontinuous phenomenon.

This is a common misperception. The twigs on an archetypal tree form a nested hierarchy. Though the tree certainly grows gradually, each twig can trace its ancestry through a distinct lineage. No matter how bushy the tree, we can cut an arbitrary limb, and each descendant branch and twig will fall from the tree. That's because each branch and twig only has a single connection to the limb.

Interestingly, the branches on a tree tend to diverge into the surrounding space in order to make best use of the available resources, i.e. solar energy; and diverging organic lineages do so for quite analogous reasons.

Furthermore, for gradualism to produce such hierarchic order it would be required that character traits once acquired can never subsequently be lost or transformed in any real sense and that the acquisition of new traits must leave previous traits essentially unchanged.

Therefore, in other words, character traits (such as hair and mammary glands unique to mammals, or pentadactyl limb unique to all terrestrial vertebrates) must remain fundamentally immutable. But why should these traits have remained immune to change, after all, are we not talking about evolution?

This statement makes no sense at all in light of the evidence. A horse's foot looks nothing like that of a mouse. A human mammary looks very little like that of a cow. And a hair follicle on a bat is quite different from that of a whale. And yet, we can trace the ancestry of these traits to a common ancestor.